Ultrasensitive impedimetric imunosensor for influenza A detection

Acute respiratory infections epidemics are yearly caused by influenza A viruses due to their high variability. The course of disease can be sometimes very severe, especially in high risk groups of patients (suffering by chronical disease, immunosupression, or patients of age over 65). The World Health Organization (WHO) estimates that annually 250-500 thousand human deaths are caused globally by the influenza viral infections. To prevent the epidemic/pandemic spread of influenza infections, careful monitoring of epidemic viruses circulating in human population is required with the aim to prepare the effective influenza vaccine. This requires an early and very sensitive diagnostics. Therefore new, rapid diagnostic methods of high sensitivity and clinical specificity are continually developed. The goal of this work was to create an ultra-sensitive and highly selective impedimetric imunobiosensor for the detection of influenza A viruses based on the interaction with monoclonal antibodies, using disposable, easy to use screen printed carbon electrodes. Electrochemical impedance spectroscopy was used to characterize the sensors and describe their basic properties. Limit of detection (LOD) and the sensitivity of the sensor from the dependence of the absolute changes of charge transfer resistance, Delta R-ct of redox probe on the logarithm of the virus protein concentration with or without modification of the electrode surface by human serum albumin (HSA) in buffered solution and horse blood were calculated. The lowest sensitivity was observed in the case of the sensor without HSA. LOD was the best in the case of the sensor without HSA in the buffered solution. In the horse blood samples LOD was almost 1000 times worse than in the previous case, however it was still good enough to be comparable with an ELISA based test. (C) 2019 Elsevier B.V. All rights reserved.